Other Lumbar Plexus Nerve Blocks

The block of the obturator nerve has virtually no indications in children for anesthetic purposes. The block of the lateral cutaneous nerve is usually performed for extending the area anesthetized by a femoral nerve block done for a muscle biopsy. With the patient lying supine, the needle is inserted perpendicular to the skin 1 cm below the union of the lateral one fourth with the medial three fourths of the inguinal ligament.^[247] As the needle penetrates the fascia lata with a characteristic give, an amount equal to two thirds of the local anesthetic is injected in a fan-shaped manner almost parallel to the skin. The needle is then withdrawn, and the remaining solution is injected superficial to the fascia lata. Brown and Dickens^[248] recommend inserting the needle above the inguinal ligament at a point immediately medial to the anterior superior iliac spine until LOR is felt as the needle enters the canal through which the nerve passes.